 #include<stdio.h>
 int main()
 {
 	int x,y;
 	scanf("%d",&x);
 	if(x<1)
 	{
 		y=x;
 		printf("y=%d\n",y);
 		
	 }
	 else if(x>=1&&x<10)
	 {
	 	y=2*x-1;
	 	printf("y=%d\n",y);
	 }
	 else if(x>10)
	 {
	 	y=3*x-11;
	 	printf("y=%d\n",y);
	 }
	 return 0;
 }
